Long story short: at the new shop that I'm working with, there are two different espresso machines from two different manufacturers. One, when you steam milk, the milk is fizzy. Not so on the other. Anyone have any idea why this would be happening? Could the steam boiler water level be too high or too low?

I haven't done any experimentation (or adjustments) yet, but I'm stumped so far. I've never seen this before. In my experience, fizzy milk comes from bad milk... but that's not the case with this. Any thoughts, folks?

Could it be of the steams content of water vapor? I´d imagine that in some circumstances wetter steam would have the foam collapse after steaming. Not sure of the chemistry behind it but had similar occurrences.

have you checked the temperatures on the fizzy machine? I've seen this a few times with various reasons:

1. the temperature is set to low (on a heat exchange) and the water basically condenses into the milk damaging the texture (i think james was alluding to this?) rather than steaming the milk properly. 2. the steam tip is inappropriate or the angle at which the steam leaves the nozzle has an impact on the end result. if the holes are too large or the pressure too high it just basically fuzzles it all! 3. also if the steam pressure is too low it wont texture properly4. the boiler is over-full, too much water will come out/not enough pressure/unbalanced.

I have worked with a couple of different machines that had a very small hole in the wand to inject air to produce more foam, I don't remember all the specifics, however I remember that covering the hole made a dramatic difference in the way it steamed (i.e. less fizzy) I wonder if a small leak at the top side of the wand would produce a similar effect?

It could be a number of things already alluded to, however if it helps I resolved the same issue on one of our Synessos this morning by tweaking the high level fill probe to lower the water level in the boiler. Pretty easy 30 second fix on a Synesso - not sure about exactly how this is done on other machines.

Edit... sorry I didn't realize this was an old thread. Haha... I'm sure you've got lovely milk by now =)